What is a Flexural Member?
A member of a structure that is subjected to both tension and compression within its depth can be called as a flexural member. As per the American Concrete Institute, the following definitions for flexural members are given:
- Slab: The slab is a flexural member with a uniform depth that supports area loads over its surface. The slab is provided with reinforcement to take the flexure either in one direction or in both directions.
- Joist - Slab: A ribbed slab is a slab that takes ribs in one or two directions.
- Beam: The beam is a flexural member that is designed to carry both uniform and concentrated loads. This member can act a primary structural element in the case of a beam-column frame or it can be used to support the slabs or the joist-slabs.
- Girder: Girders are structural members that are used in order to support the beams and designed to span between the erected columns, walls or girders. The girders are always considered to be a primary member.
Note: The beams are flexural members as it will undergo tension in the bottom and compression in the top surface under the action of load. In the case of columns, most of them are not flexural members as they are loaded at the top and the whole is subjected to compression alone. The tie bar will have only tension throughout the entire cross-sectional area. In the case of trusses, they are designed such a way that some elements take tension and another take compression. Hence none of the members in a truss configuration will be considered as a flexural member.